A conventional communication terminal device will be described with reference to FIGS. 9 and 10.
FIG. 9 shows an example of a configuration of a conventional communication terminal device in which different communication schemes or communication systems are implemented in the same communication terminal device to perform communication in parallel.
In FIG. 9, reference numeral 1000 denotes a communication unit A, reference numeral 2000 denotes a main control unit of the communication terminal device, and reference numeral 3000 denotes a communication unit B having a communication scheme different from that of the communication unit A.
Each of the communication unit A and the communication unit B performs communication in accordance with the specifications of its communication scheme and protocol.
FIG. 10 shows an operation example of the communication units A and B in the conventional communication terminal device and an example of the power consumption at that time.
The operation of FIG. 10 is based on the assumption that when data is transmitted from a communication device (not shown) corresponding to the communication terminal device of FIG. 9, each of the communication units A and B receives the data, performs data processing, and sends the result.
Each of the communication unit A and the communication unit B independently performs reception processing, data processing and transmission processing. As the operation of the communication unit A, when data is received by data reception #1, data processing is performed based on the received data, and the result is transmitted by data transmission #1. The communication unit B performs the same operation as the communication unit A. When the operation of the communication units A and B is performed as shown in FIG. 10, the power consumption is higher at the timing of transmission of each of the communication units A and B than in other cases, and the sum of the power consumptions of the communication units A and B becomes the power consumption of the communication terminal device.
However, in the operation of the conventional communication terminal device shown in FIG. 10, since each of the communication units A and B independently performs transmission/reception processing, if their transmission timings overlap each other, the power consumption at that timing becomes large, and exceeds the power consumption allowed for the communication terminal device, thereby making the communication terminal device inoperative, which is problematic.
Further, Patent Document 1 relates to a mobile phone having a communication function using a PDC scheme and a PHS scheme, and particularly discloses a mobile phone configured to stop a PHS system when a PDC system is busy by making and receiving a telephone call, and restart the PHS system when the telephone call of the PDC system is completed, and a method for reducing its current consumption.
Patent Document 1: Japanese Patent Application Publication No. 2002-152837